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Structural patterns at all scales in a nonmetallic chiral Au133(SR)52 nanoparticle.

Zeng C, Chen Y, Kirschbaum K, Appavoo K, Sfeir MY, Jin R - Sci Adv (2015)

Bottom Line: These complex surface patterns have not been observed in the smaller nanoparticles.We further demonstrate that the Au133(SR)52 nanoparticle exhibits nonmetallic features in optical and electron dynamics measurements.Our work uncovers the elegant self-organization strategies in assembling a highly robust nanoparticle and provides a conceptual advance in scientific understanding of pattern structures.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.

ABSTRACT
Structural ordering is widely present in molecules and materials. However, the organization of molecules on the curved surface of nanoparticles is still the least understood owing to the major limitations of the current surface characterization tools. By the merits of x-ray crystallography, we reveal the structural ordering at all scales in a super robust 133-gold atom nanoparticle protected by 52 thiolate ligands, which is manifested in self-assembled hierarchical patterns starting from the metal core to the interfacial -S-Au-S- ladder-like helical "stripes" and further to the "swirls" of carbon tails. These complex surface patterns have not been observed in the smaller nanoparticles. We further demonstrate that the Au133(SR)52 nanoparticle exhibits nonmetallic features in optical and electron dynamics measurements. Our work uncovers the elegant self-organization strategies in assembling a highly robust nanoparticle and provides a conceptual advance in scientific understanding of pattern structures.

No MeSH data available.


The four-shell structure of Au133(SR)52.(A to D) The first icosahedral shell with 12 Au atoms (pink) (A); second icosahedral shell with 42 Au atoms (gray) (B); third shell with 52 Au atoms (blue and cyan) (C); fourth shell with 26 Au atoms (orange) and 52 sulfur atoms (yellow) (D). (E) Layered a-b-c-b packing of Au atoms in a tetrahedral unit of an icosahedron; total of 16 such units. (F) a-b-c-a packing of atoms; total of four such units. (G) Monomeric –SR–Au–SR– motifs clamping on the third shell gold atoms. Carbon groups are omitted for clarity.
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Figure 2: The four-shell structure of Au133(SR)52.(A to D) The first icosahedral shell with 12 Au atoms (pink) (A); second icosahedral shell with 42 Au atoms (gray) (B); third shell with 52 Au atoms (blue and cyan) (C); fourth shell with 26 Au atoms (orange) and 52 sulfur atoms (yellow) (D). (E) Layered a-b-c-b packing of Au atoms in a tetrahedral unit of an icosahedron; total of 16 such units. (F) a-b-c-a packing of atoms; total of four such units. (G) Monomeric –SR–Au–SR– motifs clamping on the third shell gold atoms. Carbon groups are omitted for clarity.

Mentions: The 133 gold atoms in the nanoparticle are distributed in four shells, that is, one central atom with successive shells of 12, 42, 52, and 26 gold atoms (Fig. 2, A to D). The central atom and the first shell form a 13-atom icosahedron (Fig. 2A), which is enclosed by a second 42-atom icosahedral shell (Fig. 2B, gray), forming the 55-atom Mackay icosahedron (Au55-MI) (27). The Au55-MI can be viewed as 20 tetrahedral units joined together with a common vertex (that is, the center) through sharing three adjacent facets. The gold atoms in each tetrahedral unit are assembled in a layered a-b-c manner (Fig. 2, E and F, green-pink-gray), that is, cubic close-packing. This is indeed the first observation of the icosahedral Au55 motif, which has long been sought since Schmid et al. reported phosphine-protected Au55 nanoparticles in 1981 (28).


Structural patterns at all scales in a nonmetallic chiral Au133(SR)52 nanoparticle.

Zeng C, Chen Y, Kirschbaum K, Appavoo K, Sfeir MY, Jin R - Sci Adv (2015)

The four-shell structure of Au133(SR)52.(A to D) The first icosahedral shell with 12 Au atoms (pink) (A); second icosahedral shell with 42 Au atoms (gray) (B); third shell with 52 Au atoms (blue and cyan) (C); fourth shell with 26 Au atoms (orange) and 52 sulfur atoms (yellow) (D). (E) Layered a-b-c-b packing of Au atoms in a tetrahedral unit of an icosahedron; total of 16 such units. (F) a-b-c-a packing of atoms; total of four such units. (G) Monomeric –SR–Au–SR– motifs clamping on the third shell gold atoms. Carbon groups are omitted for clarity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643822&req=5

Figure 2: The four-shell structure of Au133(SR)52.(A to D) The first icosahedral shell with 12 Au atoms (pink) (A); second icosahedral shell with 42 Au atoms (gray) (B); third shell with 52 Au atoms (blue and cyan) (C); fourth shell with 26 Au atoms (orange) and 52 sulfur atoms (yellow) (D). (E) Layered a-b-c-b packing of Au atoms in a tetrahedral unit of an icosahedron; total of 16 such units. (F) a-b-c-a packing of atoms; total of four such units. (G) Monomeric –SR–Au–SR– motifs clamping on the third shell gold atoms. Carbon groups are omitted for clarity.
Mentions: The 133 gold atoms in the nanoparticle are distributed in four shells, that is, one central atom with successive shells of 12, 42, 52, and 26 gold atoms (Fig. 2, A to D). The central atom and the first shell form a 13-atom icosahedron (Fig. 2A), which is enclosed by a second 42-atom icosahedral shell (Fig. 2B, gray), forming the 55-atom Mackay icosahedron (Au55-MI) (27). The Au55-MI can be viewed as 20 tetrahedral units joined together with a common vertex (that is, the center) through sharing three adjacent facets. The gold atoms in each tetrahedral unit are assembled in a layered a-b-c manner (Fig. 2, E and F, green-pink-gray), that is, cubic close-packing. This is indeed the first observation of the icosahedral Au55 motif, which has long been sought since Schmid et al. reported phosphine-protected Au55 nanoparticles in 1981 (28).

Bottom Line: These complex surface patterns have not been observed in the smaller nanoparticles.We further demonstrate that the Au133(SR)52 nanoparticle exhibits nonmetallic features in optical and electron dynamics measurements.Our work uncovers the elegant self-organization strategies in assembling a highly robust nanoparticle and provides a conceptual advance in scientific understanding of pattern structures.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, USA.

ABSTRACT
Structural ordering is widely present in molecules and materials. However, the organization of molecules on the curved surface of nanoparticles is still the least understood owing to the major limitations of the current surface characterization tools. By the merits of x-ray crystallography, we reveal the structural ordering at all scales in a super robust 133-gold atom nanoparticle protected by 52 thiolate ligands, which is manifested in self-assembled hierarchical patterns starting from the metal core to the interfacial -S-Au-S- ladder-like helical "stripes" and further to the "swirls" of carbon tails. These complex surface patterns have not been observed in the smaller nanoparticles. We further demonstrate that the Au133(SR)52 nanoparticle exhibits nonmetallic features in optical and electron dynamics measurements. Our work uncovers the elegant self-organization strategies in assembling a highly robust nanoparticle and provides a conceptual advance in scientific understanding of pattern structures.

No MeSH data available.